The present invention relates to expandable and collapsible structures and, more particularly, to mechanically deployable expandable and collapsible structures.
My prior U.S. Pat. Nos. 6,141,934, 5,651,228, 5,444,946, 5,274,980, 5,230,196, RE33,710, 4,970,841, 4,838,003, 4,800,663, 4,761,929, 4,747,239, 4,689,932, 4,666,102, 4,637,180, 4,579,066, 4,561,618, 4,522,008, 4,512,097, 4,473,986, 4,437,275, 4,334,660, 4,290,244, 4,280,521, 4,026,313, and 3,968,808 are incorporated by reference and show various collapsible structures and components therefor. Many expandable and collapsible structures are designed to be erected by workers at ground level. Typically, the workers erect center portions of the structures first, then work their way outward to erect more peripheral portions of the structure. When the erection of the structures is completed, the center portions may be out of the reach of the workers, such as is likely to be the case in the erection of certain of the structures disclosed in U.S. Pat. No. 5,444,946. While experienced workers can often erect these structures in relatively little time, it usually takes a team of workers to erect the structures. Additionally, when the structures are unfolded to a collapsed condition prior to forming the erected structure, the peripheral portions of the structures typically extend outwardly substantially beyond the boundaries of the erected structure because the structures are laid out substantially flat prior to erection into their final shape. This can make it necessary to attach covers to the structures only after the structures are erected because the structures are designed to cover the structures in the erected condition.
It is desirable to provide an expandable and collapsible structure that can have a cover that is attached to the structure when the structure is folded or expanded. It is also desirable to provide a structure that does not need a team of workers to erect the structure.
In accordance with one aspect of the present invention, a mechanically deployable, expandable and collapsible structure is provided. The structure includes at least one scissor assembly comprising a first and a second strut, the first and the second strut each having first and second ends and being pivotably attached to each other such that the scissor assembly is movable between a folded position in which the first end of the first strut and the second end of the second strut are substantially adjacent and an expanded position. The structure also includes a first spacer disposed between the first end of the first strut and the first end of the second strut when the scissor assembly is in the expanded position, and a second spacer disposed between the second end of the first strut and the second end of the second strut when the scissor assembly is in the expanded position. A tension member is connected to the first and second struts. The tension member is arranged such that the scissor assembly is moved from the folded position when there is slack in the tension member to the expanded position when the slack in the tension member is taken up.
In accordance with another aspect of the present invention, a method of deploying a mechanically deployable structure is provided. According to the method, the structure is unfolded to a collapsed condition. The structure includes at least one scissor assembly comprising a first and a second strut, the first and the second strut each having first and second ends and being pivotably attached to each other such that the scissor assembly is movable between a folded position in which the first end of the first strut and the second end of the second strut are substantially adjacent and an expanded position. When the structure is in a collapsed condition, slack in a tension member is taken up, the tension member being connected to the first and second struts in such a manner that taking up slack draws the first ends of the first and second struts toward one another.